Neurons
that originate in the eye's retina travel to the LGN before traveling to the
back of the brain to connect at the primary visual cortex (V1). From
the primary visual cortex they fan out and make connections at a number
of secondary locations in the back of the brain devoted to processing
visual information.

Some of these neurons are grouped together to form
a pathway. One of these pathways, made up of large-sized neurons, is
called the Magnocellular, or M-pathway. The M-pathway processes the information captured by 'Rods' in the Retina (2.1 The Retina: Rods and Cones). Harvard professors Livingstone and Galaburda
looked at the subdivision of the LGN that holds the cells in the
M-pathway and found that the cells are smaller in people with dyslexia
compared to non-dyslexics.

Rods processed by the M-pathway, are found in the peripheral view of our eye, the see in black, white, and shades of gray and tell us the form or shape that something has. They are super-sensitive, allowing us to see when it's dark.

specifics

Peripheral

Contrast and Movement

High sensitivity (Night Vision)

More photopigment capture more light

High amplification, single photon detection

Saturate in daylight

Low temporal resolution

Slow response, long integration time

Sensitive to scattered ligh

Conclusion: In our brain every part is interlinked, a smaller M-pathway leads to a less filtered input-stream of motion and orientation, from the eye's Retina to the Primary Visual Cortex (V1) in the back of our brain. Resulting in a weaker alignment system that makes it harder for dyslexics to have a Visual Grip (5.2 Visual Grid and the Origin of Ocular Dominance Patterns in V1) and causing Visual Stess. Dyslexia related deficits are also found in the Hippocampus where stress can create memory problems. (11.3 DCDC2 & Dyslexia).